Fiber optic systems have many advantages on the basis of the communication systems technology compare to metallic media communication. These advantages include lower interference, small signal attenuation and bandwidth characteristics. In addition, relatively small cross-section of the fiber optic cable from a substantial growth in capacity in the existing lines is replaced. Properties of optical fibers can be classified as linear and nonlinear. Non-linear properties are influenced by parameters such as bit rate, channel spacing, and the level of performance. (more…)

Green computing has forced even the largest companies to rethink and refocus to use energy more efficiently. We have low-power processors, motherboards, memory modules, hard drives and technology energy efficiency even higher. But still, there are many devices that need to be look at if they are efficient enough. You still need to look at each individual product like LCD and CRD monitor displays to decide whether their effectiveness in reducing your monthly electricity bills.

Most of the nation’s approximately 61 million monitors are associated with desktop PCs and workstations, whereas some 13 million displays rely on video input (as seen in airports). (more…)

Electrodynamic Suspension (EDS) can be viewed as an array of magnets moving over a conducting sheet and being pushed upwards by forces due to induced currents. This electrodynamic suspension that was pioneered by Gordon Danby and James Powell in the 1960s, can not work at zero speed, but at higher speeds it can be inherently stable. The virtue of Electrodynamic Suspension designs is their ability to operate with larger air gaps than is feasible with Electromagnetic Suspension EMS designs. (more…)

Electromagnetic Suspension (EMS) system in which an array of magnets is attracted upwards to a steel rail. It is possible to design the magnets so that there is an upward force produced by magnetic attraction that cancels the downward gravitational force: the magnets are suspended in space! If steel beams were mounted on either side of a “guideway,” then a vehicle with magnets on both sides could move along the guideway and be supported and guided by the steel rails. (more…)

The term hybrid energy system refers to those applications in which multiple energy unit conversion devices are used together to supply an energy requirement. These systems are often used in isolated applications and normally include at least one renewable energy source in the configuration. Hybrid energy systems are used an alternative to more conventional systems, which typically are based on a single fossil fuel source. Hybrid energy systems may also be used as part of distributed generation application in conventional electricity grid. (more…)

The term cryogenics derives from the Greek kryos, for icy cold. The upper limit that characterizes the cryogenic region of the temperature scale is subjective. If the delimitation criterion takes into consideration practical reasons, then this upper limit can be established at a higher than usually declared value (120 K) in order to include natural gas fuel liquefaction. The cryogenics region of the temperature scale 0–120 K can be divided into sub regions according to the criteria of the cryogenic method and refrigerant (known as crycoolers) as follows: (more…)

The idea of using an absorption fluid as a refrigerant carrier derived from the drawback of VCR (vapor–compression refrigeration) systems that the gas compression requires a high work input. A pump that requires practically no work to increase the pressure in the refrigeration system replaces the complicated and work-consuming compressor. There are two major advantages of absorption refrigeration systems (ARSs) compared with VCRs (vapor–compression refrigeration): No CFCs or HCFCs are used as refrigerants, and they use heat from different sources, such as combustion, industrial processes, waste heat (an economical solution for recovery), or solar heat. (more…)

A propulsion alternative is to transfer power to the vehicle and then have a magnetic structure on the vehicle that can create a moving field that, in turn, interacts with a conducting guide way to provide propulsion. This is called a short stator linear induction motor (or linear asynchronous motor), generally referred to as a Linear Induction Motor. It is possible to put the powered winding on the guide way and induce currents in a conductor on the vehicle, in which case it would be a long stator design, but this turns out to be an expensive and inefficient approach to maglev propulsion. (more…)

There are literally thousands of uses for lasers. One of the largest applications is telecommunications—sending a signal through fiber optic cables, for example. This application grew rapidly in the 1990s with the phenomenal increase in traffic on the Internet. Optical data storage, such as on compact disks, CD-ROMs, and DVDs, is another important use for lasers. The information age was obviously a boon to this application, and as researchers obtained smaller wavelengths with diode lasers, they were able to fit more information on smaller storage devices. (more…)

The demand for electric energy by a community varies with the time of day and with the time of year. An electric power utility must be prepared to meet these demands. This poses an engineering problem because there is no practical method of storing electric energy on a scale that will meet the demands of a large community. To meet short-term increases in demand, electric utilities employ power generators that can be turned on and off on short notice. For example, they may use a gas turbine similar to a jet plane engine to drive a generator. Another scheme is to use a pumped storage hydroelectric system. Such a system does not rely on nature to replenish the water in a reservoir but rather uses electrically run pumps. Importantly, the system can generate electricity on short notice.

Water is forced to an elevated reservoir by a motor-driven turbine. The water in the reservoir has gravitational potential energy by virtue of the work done on it. When electricity is needed, the water is allowed to flow downward into the turbine that drives the magnetic generator motor, which now functions as an electric generator. The energy required to elevate the water is never completely recovered in the process. Nevertheless, the system is economical because the reservoir can be filled when electric energy demands and costs are low. It is also possible to have a system in which water flows from ground level to underground turboelectric perpetual generators. In this case, work has to be done to restore the water to ground level.

Taking into account losses due to evaporation of surface water exposure and energy unit conversion losses, it is estimates that approximately 70% to 85% of the electricity used to pump water into the elevated reservoir can be recovered. The technique is currently the most effective way to store large quantities of electrical energy in the form of energy operation, but the cost of capital and the presence of appropriate geography critical factors for the decision.

With energy management, well to pump storage hydroelectric systems for controlling the frequency of food production and security of reserve magnetic power generator. Thermal plants are much less able to responds in the sudden changes in electricity demand, the frequency and voltage to cause instability. Pumping stations, like other water plants can respond to changes within seconds to load with pumped storage hydroelectric system.